Sheet material forming apparatus



H. G. FLAGLER SHEET MATERIAL FORMING APPARATUS Aug. 3o, 1960 4 Sheets-Sheet 1 Filed April 21. 1954 Aug.'30, 1960 H. G. FLAGLER 2,950,697

SHEET MATERIAL FORMING APPARATUS Filed April 21, 1954 4 sheetssneet 2 All l' f' imllllll S1 lw'mmn A l 'A'. t

Aug. 30, 1960 H. G. FLAGLER SHEET MATERIAL FORMING APPARATUS 4 Sheets-Sheet 3 Filed April 2l. 1954 Aug. 30, 1960 H. G. FLAGLER 2,950,697

SHEET MATERIAL F'ORMING APPARATUS Filed April 2l, 1954 4 Sheets-Sheet 4 fw a ilimited States EPatent @Eden '2,950,697 'Patented Aug. 3o, 1960 srmur MATERIAL FoRMtNG APPARATUS Harold G. Flagler, Oak Park, lll.; Juanita Flagler, executrx of the estate of Harold G. Flagler, deceased ined Apr. 21, 1954, ser. No. 424,718

11 claims. (ci. 11s-s4) This invention relates to improved sheet material forming apparatus and more particularly to improved apparatus adapted to form a seam or joint between two elements of sheet material irrespective of the sizes thereof.

It is a principal object of this invention to provide improved apparatus for forming a seam or joint between two elements of sheet material of unlimited size.

Various apparatus has heretofore been proposed for working, joining and shaping sheet material. This apparatus is used extensively in the sheet metal arts, and especially in connection with heating and Ventilating installations and duct construction. Apparatus has heretofore been provided for forming a bead or flange along the edge of sheet metal by operating on successive increments thereof, and such beads or flanges may be engaged by corresponding anges of other similar elements and the assembly subsequently rolled or hammered to form -a seam between the two elements. However, such a construction requires extensive attention by an operator and one or more manual operations.

A second means for forming seams between elements of sheet material includes the use of large devices, such as press brakes, which produce a ange along the entire edge portion of an elongated sheet, the flanges of two such sheets then being engaged and hammered or rolled into locking relationship. Such manually produced joints are generally unattractive, obviously the result of manual operation, of limited length, and usually below the required or desired strength.

It is, therefore, a further object of this invention to provide improved apparatus for forming a joint between two elements of sheet metal substantially independent of the size of the pieces, the thickness of the material or the type of metal of which the sheets are formed.

lt is another object of this invention to provide an improved single integral piece of apparatus which will perform all of the necessary operations to produce a seam between two elements of sheet material irrespective of the physical dimensions thereof.

lt is another object of this invention to provide improved apparatus for forming a seam in sheet material which requires an extremely low energy input.

It is a further object of' this invention to provide irnproved sheet metal seaming apparatus which operates on successive incremental portions of adiacent edge portions of two elements of sheet material whereby a joint is progressively formed therebetween.

lt is another object of this invention to provide improved sheet metal seaming apparatus which employs reciprocating forming tools having substantial inertia, thus reducing the primary power requirements for the metal deformation.

lt is an additional object of this invention to provide improved sheet metal forming apparatus having a sequence of forming tools, certain of which are oppositely disposed in the arms of a yoke whereby a continuous joint of unlimited length may be formed.

It is still another object of this invention to provide improved sheet metal forming apparatus which is small and inexpensive and consequently well adapted for use in the small shop or in the eld.

Further and additional objects of this invention will become manifest from a. consideration of this specification, the accompanying drawings and the appended claims.

In one form of this -invention apparatus is provided having -a plurality of forming and working tools aligned in linear relationship and driven by a common source of energy. More particularly a plurality of forming tools are aligned along opposite arms of a yoke-like member whereby corresponding edge portions of two elements of sheet material passed therethrough are progressively formed to have interlocking lianges, the nal steps in theV formation of the interlocking flanges being performed by the tools suspended in the arms of the yoke whereby an integral sheet of unlimited size formed of the two sheet material elements may be produced.

In the embodiment disclosed herein the following steps are performed on the adjacent edge portions of two sheet metal elements which are to be joined. The edge portions are clamped in overlying spaced relationship and are intermittently fed along linear convergent paths. A 4iiange is formed along each of said edge portions, the flanges being disposed in generally parallel spaced coextensive relationship. The flanges and edge portion are passed into the area between the arms of the supporting yoke where an additional :tool forms the flanges to elect an engagement therebetween at an angle to the elements of sheet material. A pair of oppositely disposed rollers eifect convergence of the two elements of sheet material whereby the ilanges are flattened therebetween in interlocking engagement. The final step in the process of forming a seam between two elements of sheet material comprises passing the seam between a pair of rollers to produce a lip on one of the elements which engages the flange of the other element, producing a rigid joint therebetween.V The manner in which these various steps are performed will be manifest from a consideration of the drawings and description to follow.

For a more complete understanding of this invention reference will now be made to the accompanying drawings wherein Fig. 1 is a View of the front elevation of one embodiment of this invention;

Fig. 2 is a view in section of the embodiment of Fig. l, taken along the line 2-2 of Fig. 1;

Fig. 3 is a bottom View of the embodiment of Fig. l;

Fig. 4 illustrates the bight portion of the yokelike frame of the embodiment of Fig. l;

Fig. 5 partially illustrates the actuating mechanism of the embodiment of Fig. l;

Fig. 6 is a view in section of the embodiment of Fig. l, taken along the line 6-6 of IFig. l;

Fig. 7 is a sectional view illustrating the driving rollers, taken along the line '7 7 of Fig. 1;

Fig. 8 illustrates the flange forming tools of the ernbodirnent of Fig. l, taken along the line 8 8 thereof;

Fig. 9 is a partial elevational View illustrating the flange forming elements of this invention;

Fig. 10 is a partial perspective view showing the ange forming tools and the manner in which they engage the sheet material;

Fig. 1l is a view in section of the embodiment of Fig. l, taken along the line 11-13. and illustrating the angular flange forming tools in operation;

Fig. 12 is a partial perspective view showing the angle forming tools in operation on two adjacent edge portions of sheet elements to be joined;

Fig. .13 is a view in section, taken along the line 13-13 of Fig. l illustrating the element converging rollers; and

Fig. 14 is a View in section taken along the line 14-14 of `Fig. l, showing the lip forming-rollers of the embodi-` ment illustrated therein.

Referring now to the drawings, and more particularly to Figs. l, 2 and 3, a small portable sheet metal seaming device 2i? is provided comprising a plurality of metal working tools, all driven from a common source of power such as an electric motor 212, and mounted in a frame 24. The frame 24 comprises a pair of elongated arm portions 26 and 2S secured in spaced parallel relationship by an intermediate bight portion 30. The armsV 2-6 `and 23 and the bight portion 30 are rigidly clamped together to form an integral structure by a plurality of bolts 32 extending through appropriate apertures formed in the arms and threadably engaging corresponding aper-` tures 34 in the bight portion'30.

The elements of sheet material to be joined are shown in'li'g. l disposed along the engaging'portio'ns of the `big-ht 3% and the associated arms 26 -and 28. The upper element Seis disposed in a generally horizontal plane in a slot formed between arm 26 and bight element 30. Similarly, lower sheet metal element 38 is disposed in a generally horizontal plane and in -a slot formed between lower arm 28 and bight 3). The planes of the ltwo elements 36 land 35 are generally horizontal but convergent Yfrom an approximate one-half inch spacing at the right of Fig. l to juxtaposition at the left edge thereof. There is also an intermediate portion in which the elements are juxtaposed for engagement by a driving means. As shown in Fig. 6 the edge portions of the element 36 overlie that of element 33 substantially, the exact dimension of the overlying portion and the perpendicular distance therebetween depending upon the nature of the joint to be formed.

fect engagement of lower knurled wheel 68 with lower element 38 and thus elements 36 and 3S will be driven together. Flanges 63 and 69 `are formed on wheels 62 and 63 respectively to insure maintenance of the desired spaced relationship between the elements 36 and 38. Upon actuation of handle 48 the sheet elements 36 and 38 are driven in a `direction generally parallel to the arms 26 and 2S and into engagement with a second set of knurled driving wheels 74 and 76. The driving wheels 74 and 76 are keyed to shafts 7S and 30 and have associated therewith appropriate driving gears 82 and 83. The shafts 78 and S0 arefreely mounted in elongated apertures in arms 26 and 28 and associated plates 27 and 29 rotation in the driving gears, as well as to provide'desired In one embodiment of this invention Vadapted for use i on the familiar galvanized sheet iron used in air conditioning work, it has been found desirable to have the two edge portions overlap approximately one inch and perpendicular-ly spaced approximately one-half inch apart. The elements of sheet metal 36 and 38 are rst placed in the slots 42 and 44 so that they abut the edges of the arm portions 26 and 2S respectively and also abut a pin 46. Pin 46 is slidable in apertures formed through the upper Iarm 26 and the bight 3G and a small depression in the lower arm 28. Thus, with the two elements aligned against the edge of the respective arms 26 or 2S and the pin 46 their relative positions are accurately established for further forming operations. Operation of the apparatus is now initiated by depressing the handle 48 which is pivotally mounted through pin 50 in bracket 51 which is integral with arm 26. Handle 48 has an apertured extension 52 adapted to engage an enlarged end or head 54 of the pin 46. By depressing handle the pin is withdrawn from the slots 42 and 44 to permit the elements to proceed therethrough. Actuation of handle 48 also rotates a cam face 56 which engages a pin 5S, Vcompressing resilient insert 60, to effect engage ment of a knurled driving wheel 62 with the upper sheet Velement 38 as best shown in Fig. 7. The knurled driving wheel 62 is keyed to a shaft 64 which is rotatably mounted between the upper arm 26 and an associated side plate 27 of frame 24. Also keyed to the shaft64 is `a driving gear 66 whereby power applied to the the driving gear 66 to produce rotation thereof will rotate the driving wheel 62 and effect linearV motion of the upper sheet element 36. This motion will be to the left in Fig. l. r[he shaft 64 rests in a vertically elongated aperture in Aarm 26 whereby the desired vertical movement of the wheel 62 may be effected.

Similarly a knurled driving wheel 68 and spur gear 70 are keyed to a common shaft 72 rotatably mounted in the lower arm 28 and associated side plate 29 of fname 24. lt will be clear that actuation of handle 4S will efand continuously urged' byY resilient means into engagement with sheet elements 36 and 38. The driving gears d2 and S3 are in engagement with intermediate gears 84 which are necessary to produce the proper direction of spacing therebetween.

The edge portions of the elements now undergo a plurality of forming operations, the nature and sequence of which will be clear from a consideration ofcross section views S, ll, 13 and 14 in that order. The sheet elements 36 and 38 are driven into a portion of the slots 42 and 44 into which reciprocating ange forming tools 86 and S8 are operating. The ange forming tools 86 and 88 will oscillate in Va predetermined manner, whereby they will engage the `sheet elements only during a period in the operation during which the sheet elements are not in motion. The driving means for producing the desired intermittent motion of the elements and thertools will be described subsequently.

The upper tool S6 is slidably mounted in the upper arm 26 and has a pin 90 extending therefrom and engageable in an elongated slot formed in bell crank 92 which is pivotally mounted on pin 94 secured inV upper arm 26. A driving `arm 96 pivotallyengages the free end of bell crank 92 and is adapted vfor oscillatory motion. Thus, as shown clearly in Figs. 8 and 9 oscillatory horizontal motion of driving arm 96 will produce vertical motion of the flange forming tool 36 through bell crank 92. The elements necessary for actuation of the corresponding lower iiange forming tool 88 are very similar to those just described diifering therefrom only in the positioning of bell crank 98 and the length of driving arm 1%. This alternate positioning of the bell crank is necessary so that the forming tools S6 and S8 lwill move into engagement with the sheet elements coincidently, though the motion of the driving arms 96 and 190 is of an opposite sense as will be clear from a description of the driving mechanism which follows. The incremental step provided for forward motion of the sheet elements being operated upon is small compared to the length of the forming tools 86 and 88. Thus, the formation of the flanges 162 and 104 is of a gradual nature as shown in Figs. 9 and l0. As shown most clearly in Fig. l0, the forming tools 86 and 38 have a shaped element engaging portion 166 and -a ilat element engaging portion 108, the fiat and shaped portions being disposed at substantially to one another. The adjacent portion of the bight 3i) is cut and shaped to cooperate with the tool 88, thusY forming a sharp ange normal to the sheet element. As shown in Fig. 4 the forward portion of the bight 3i) has parallel rectangular grooves 114 and 116 therein which receive the forming tools 86 and 88. The ilanged elements proceed through the apparatus of this invention disposed in the manner shown in Fig. 8. The combination of the flanges 102 and 104 and the inmediately adjacent portions of the elements 36 and 3S produce a boxlike conliguration which passes between an additional pair of driving wheels and 112. Driving wheels 110 and v112 lare provided with diange portions 'which extend into grooves 114 and 116 respectively and are positioned at the extreme forward end thereof lwhere the grooves 114 and 116 extend through the bight 30. The cooperagoeden? tive action of the flange wheels and grooves clamp the anged edge portions of the elements in the box-like relationship just described and may aid in the forming operation. The wheels 110 Iand 112 are keyed to shafts 118 and 120 which also have driving gears 122 and 124 keyed respectively thereto. The gears 122 and 124 are in engagement with idler gears 126 and 128 which are, in turn, in engagement with the gears 82 and 83 already described.

The sheet elements proceed to the next operating position in the forming apparatus rand are engaged at said position by a pair yof pivotally mounted bending vtools 130 and 132. The tools 130 and 132 rotate about vertical axes to engage the corresponding anges 102 and 104 Vand form them inwardly into juxtapositionv between the elements 36 `and 38. Fig. 1l illustrates the manner in which the flanges appear after formation by the tools 130 and 132.

Fig. 12 is an isometric view showing the two sheet elements and portions of the bending tools to clearly illustrate the manner in which said tools function. The upper bending tool 130 is secured to a vertical shaft 134 which is fixed to a link V136 driven in an oscillatory manner by a rod 1138 pivotally connected to link 136 through pin 148. Rod 138 will be reciprocated in synchronism with the motion of drive rod 96 which actuates the vertical ange forming tool already described and is secured thereto at the driving end by pivot 97. Thus, while ange forming tool 86 is operating on an incremental portion of the upper sheet element 36 the bending tool 130 is operating on a second previously anged incremental portion. The bending tool 130 is spaced a substantial distance from the flange forming tool 86 and is adapted to bend the flange 102 inwardly into an angular disposition relative -to the element 36 and underlie the edge portion thereof. The lower bending tool 132 is similarly secured to `a rotatably mounted shaft 142 having an oscillatory link 144 secured to the opposite end thereof, said link being connected to a reciprocating arm 146 through a pin 148. The lower bending tool 132 will function in the same manner as the tool 13G just described and in synchro-msm therefore to similarly bend ange 104 of lower sheet element 38.

Referring once again to Figs. l and 2 the sheet material proceeds to the next operative position in the apparatus 20 where it is engaged by a pair of spaced forming rollers 150 and 152. The rollers 150 and 152 are ixed to shafts 154 and 156 which also have spur gears 158 and 160 secured respectively thereto. Spur gears 158 and 160 are in engagement with corresponding idler gears 162 and 164 and are thus intermittently rotated in synchronism with the driving gears 122 and 124, and 82 and 83. The rollers 150 `and 152 are so spaced, as illustrated in Fig. 13, that the angle between the sheet elements 36 and 38 and their respective flange portions 102 and 104 is substantially reduced. The rollers 150 and 152 are also provided with anges 166 and 168 respectively which serve the dual function of maintaining the position between the two sheet elements 36 and 38 and providing driving engagement between the flange and the knurled portions 170 and 172 onthe respective opposed rollers. The shaft 154 is loosely mounted in an elongated aperture 174 formed in the upper arm portion 26 of the frame 24. The shaft 154 is uniformly urged downwardly into engagement with the sheet element 136 by a resilient member 176 adjustably supported in a vertical aperture between the shaft 154 and an adjustable means such as bolt 178 which is threadably secured in the arm 26. The degree to which the sheet elements 36 `and 38 are brought together in this operation is a matter of design and the rollers may be so adjusted that the sheet elements and flanges may be formed into substantially parallel juxtaposed relationship.

The joint thus formed would lack rigidity, as -a slight compressive force applied to the edges of sheet elements 36 `and 38 could effect disengagement of the flange p61"- tions. Therefore, referring once again to Fig. 1, a final pair of forming rollers 188 yand 182 is provided to produce a locking lip 184 in one of the sheet elements 36 whereby the two sheet elements are rigidly secured together and will not become disengaged though substantial transverse force is applied thereto. The locking lip 184 is most clearly shown in the sectional View of Fig. 14. Therein it can be seen that the lower roller 182 has a substantially iiat periphery while the upper roller 180 has Va reduced central portion 186 which receives the multiple thicknesses of material which comprise the seam. Thus, the portion of upper sheet element 36 which is adjacent to the seam is engaged by the curved portion 188 of roller 180 and is formed thereby to produce the lip 184 to lock the joint. Rollers 180 and 182 are secured to shafts 190 `and 192 along with their respective driving gears 194 and 196. The gears 194 and 196 are engaged respectively by idler gears 198 and 200 which are in turn intermittently driven by gears 158 and 16). The upper roller 180 is urged toward engagement with the lower roller 182 in the same manner as that described with respect -to Fig. 13, namely, the shaft 190 is freely mounted in an elongated `aperture 202 formed in the upper arm 26. The shaft 190 is uniformly urged downwardly by resilient means 284 which is compressed between the shaft and a bolt 206 which is threadably secured in the upper arm 26. All of the shafts shown for mounting driving and forming elements are secured in the respective housings by machine nuts and lock washers in the usual marmer.

The various driving and forming elements described are all driven from a common energy source, namely, electric motor 22. Motor 22 is connected to a collar 288 having a pin 210 eccentrically disposed therein. Pin 210 extends through an aperture formed in a driving arm 212 which consequently reciprocates for uniform rotary motion of the motor. At the other end of arm 212 a block 214 is secured by bolt 217. Block 214 is pivotally mounted to arm 216 which in turn is pivotally secured to the upper arm portion 26 of frame 24 through pin 21S. Arm 216 will effect opposite reciprocatory motion in upper driving arm 96 and lower driving arm 100. A detent 22) is pivotally mounted on arm -96 about pin 222 and has a finger 224 extending therefrom normally urged into engagement with idler gear 84 by helical spring 226 which is compressed between associated portions of the arm 96 and the detent 220. A similar detent 228 is pivotally mounted about pin 230 which is secured to the lower driving arm 100. The detent 228 has a finger 232 urged into engagement with driving gear by a coil spring 234 which is compressed between a shoulder 236 on the detent 228 and a spaced extension 23S on the driving arm 100. The driving arms 96 and 100 engage bell cranks 92 and 98 to actuate the vertically movable ange forming tools -86 and 88 as already described. For each reciprocation of the driving crank 216, the chain of spur gears in the upper and lower arms 26 and 28 are actuated through a predetermined angular step by detents 220 and 228. During the reverse stroke of the driving arm 216, the -arm 138, carried by the upper driving arm 96, actuates the upper bending tool 130, and the lower arm 146, pivotally connected to lower driving arm 100 through bolt 147, effects reciprocation of the lower bending tool 132. At the same time that bending tools 130 and 132 are in engagement with the elements, ange forming tools 86 pivotally mounted on arm with the gear engaging Vthe arm portions 26 and 28. Thus in one embodiment the arm portions have a cross section `of approximately tive inches square and closed members, such as ducts,

therefrom in opposite directions, means deforming longitudinal increments of the outer portion of eachV of said edge portions toward the other element, the width of said outer portion being less than the spacing between might be formed having dimensions only slightly larger than this value. Furthermore, the embodiment disclosed herein is approximately 24 inches in length and can be adequately powered by a 1A h p. motor. The entire apparatus, including the motor weighs less than 100 pounds and is thus of great value in the small shop.

The purpose of the apparatus taught by this invention is the production of a seam between two sheets or sheet portions of metal or other deformable material irrespective of the size or shape of the joined elements.

This is accomplished by the utilization of a unique small series of forming tools mounted in a yoke-like frame whereby the inal forming and locking operations are performed beyond the bight portions of the yoke.

Wherever, throughout the specitication and claims, the terms sheets, sheet portions, sheet elements or the like are used, it is to be understood that such elements may be separate sheets, or portions of a common sheet formed into a closed body.

This disclosure further teaches the novel advantages of utilizing reciprocatory forming tools whereby a smaller source of continuous power may be utilized by gaining the advantages of high accuracy in the tool elements.

Without further elaboration, the foregoing will so fully explain the character of my invention that others may, by applying current knowledge, readily adapt the same for use under varying conditions of service, while retaining certain features which may properly be said to constitute the essential items of novelty involved, which items are intended to be dened and secured to me by theY following claims.

I claim:

1. Apparatus for forming a seam between two elements of sheet material, said apparatus comprising means for supporting corresponding elongate edge portions of said two elements in overlying spaced substantially parallel relationship with said elements extending outwardly therefrom in opposite directions, means deforming longitudinal increments of the outer portion of each of said edge portions toward the other element, the width of said outer portion bein-g less than the spacing between said edge portions, means further deforming said increments of the outer portion to angularly overlie the inner portion of the same element whereby the outer portions of said two elements are in substantially parallel contiguous relationship, means for gradually converging said inner portions of said two elements together with said outer portions therebetween, the outer portion of each of said elements being entrapped between the inner and outer portions of the other of said elements, means for driving said edge portions through the deforming means, the further deforming means, and the converging means whereby a continuous interlocking joint is formed between the inner and outer edge portions of said two elements, and frame meansV supporting all of said foreging means in a generallyY aligned operative relations p.

2. Apparatus for forming Va seam between two elements of sheet material, said apparatus comprising means for supporting corresponding elongate edge ,portions of said two elements in overlying spaced substantially paral- .lel relationship with said elements extending outwardly said edge portions, means further deforming said increments of the outer portion to angularly overlie the inner portion of the same element whereby the outer portions of said two elements are in substantially parallel contiguous relationship, means for gradually converging said inner portions of said two elements together with said outer portions therebetween, the outer portion of each of said elements being entrapped between the inner and outer portions of the other of said elements, means for progressively forming a longitudinal offset in one of said elements adjacent said inner portion to abut the inner portion of the other of said elements and maintain the latter inner portion in place'between the portions of said one element, means for driving said edge portions through the deforming means, the further deforming means, the otfsetting means, and the converging means whereby a continuous interlocking joint is formed between the inner and outer edge portions of said two elements, and Vframe means supporting all of said foregoing means in a generally'aligned operative relationship. 3. Apparatus for forming a seam between two elements of sheet material, said apparatus comprising a yoke member having a bight portion and two coextending elongate arm portions, said bight portion defining two oppositely disposed elongate passages in spaced partially overlying relationship aligned with the space between said arm portions, driving means adapted to engage the elongate edge portions of said two elements when disposed in said passages and longitudinally move said edge portions in generally parallel spaced relationship, forming means in said bight portion to progressively engage the outer portion of each of said edge portions and deform each of said outer portions toward the other of said elements to form an acute angle with the inner portions, the width of said outer portions being less than the spacing between said elements, and means in said arm portions to converge said inner portions withy die means to engage Vsaid substantially normal outer' portions and urge said outer portions together in parallel relationship angularly disposed with respect to said elements.

6. The apparatus of claim 3 wherein aligning means selectively movable intotsaid slots is provided whereby said elements may be aligned thereby prior to the formation of aseam.

7. Apparatus for forming a seam between two ele-v ments of sheet material, said apparatus comprising a yoke member having a bight portion and two coextending arm portions, oppositely disposed elongated slots being formed in vsaid bight portion to receive said two elements Ywith corresponding edge portions maintainedy in spaced overlying relationship, guide means in said yoke member to guide said edge portions therethrough in predetermined spaced, generally parallel overlying re-A lationship, said edge portions Ibeing approximately twice the width of said seam and spaced apart at least the width of said seam, driving means for longitudinallyv moving said edge portions through said slots toward said Aarm portions and between saidV arm portions in a direc-' tion substantially parallel thereto, means mounted in opposed relationship in saidyoke member to engage` a portion of each of said edge portions and form generally transverse coextending spaced flanges thereon, bending means mounted in opposed relationship in said arm portions to engage said anges and form said anges inwardly into abutting relationship forming an acute angle with said elements, means mounted adjacent said bending means in opposed relationship in said arm portions for efecting convergence of said elements normal to the plane of said elements to retain said flanges therebetween, and means mounted adjacent said converging means in opposed relationship in said arm portions for receiving said converging elements and for forming a lip in one of said elements and abutting the adjacent edges of said flange portions.

8. Apparatus for forming a seam between two elements of sheet material, said apparatus comprising frame means, driving means for moving corresponding edge portions of said two elements relative to said frame means and in predetermined overlying spaced relationship, guide means in said frame means to guide said edge portions therethrough in predetermined spaced, generally parallel overlying relationship, said edge portions being approximately twice the width of said seam and spaced apart at least the width of said seam, means to effect convergence of said elements normal to the planes of said elements, forming means mounted in said frame to engage the outer portions of said edge portions of said elements coincidentally with said convergence to form interlocking flanges therealong, and means to form a lip in one of said elements adjacent said anges to lock said elements together.

9. Apparatus for forming a seam between two elements of sheet material, said apparatus comprising frame means, driving means for moving corresponding edge portions of said two elements relative to said frame means and in predetermined overlying spaced relationship, guide means in said frame means to guide said edge portions therethrough in predetermined spaced, generally parallel overlying relationship, said edge portions being approximately twice the width of said seam and spaced apart at least the width of said seam, forming means mounted in said frame to engage the outer parts of said edge portions of said elements to form interlocking tianges therealong, means for electing the convergence of said edge portions to compress the flanges therebetween, and means to form a lip in one of said elements adjacent said flanges to lock said elements together.

l0. Apparatus for forming a seam between two elements of sheet material, said apparatus comprising frame means, driving means for moving corresponding edge portions of said two elements relative to said frame means and in predetermined longitudinally aligned spaced relationship, guide means in said frame means to guide said edge portions therethrough in predetermined spaced, generally parallel overlying relationship, said edge portions being approximately twice the width of said seam and spaced apart at least the width of said seam, forming means mounted for vertical oscillation in said frame to engage increments of the outer parts of said edge portions to form transverse coextending flanges therealong, bending means mounted in said frame for horizontal oscillation to incrementally bend said anges into engagement and angular disposition relative to said elements, roller means mounted in said frame to eiect convergence of said elements whereby said `angular flanges are clamped in interlocking engagement therebetween, and means for synchronously actuating said forming means, bending means, and roller means with said driving means.

11. Apparatus for forming a seam between two elements of sheet material, said apparatus comprising frame means, driving means for moving corresponding edge portions of said two elements relative to said frame means and in predetermined longitudinally aligned spaced relationship, guide means in said frame means to guide said edge portions therethrough in predetermined spaced, generally parallel overlying relationship, said edge portions being approximately twice the width of said seam and spaced apart at least the width of said seam, yforming means mounted for vertical oscillation in said frame to engage increments of the outer parts of said edge portions to form transverse coextending anges therealong, bending means mounted in said frame for horizontal oscillation to incrementally bend said flanges into engagement and angular disposition relative to said elements, roller means mounted in said frame to eiect convergence of said elements whereby said angular flanges are clamped in interlocking engagement therebetween, roller means mounted in said frame to form a lip in one of said interlocked elements adjacent the ange thereof to retain the ange of the other of said elements therebetween, and means for synchronously actuating said forming means, bending means, and roller means with said driving means.

References Cited in the le of this patent UNITED STATES PATENTS 1,163,784 Skinner Dec. 14, 1915 1,378,651 Brown et al May 17, 1921 2,012,889 McIntyre Aug. 27, 1935 2,015,804 McGarry Oct. 1, 1935 2,025,750 Ingels --.a DEC. 31, 1935 2,566,423 Miller Sept. 4, 1951 2,682,850 Close July 6, 1954 

